# frozen_string_literal: true

module DiscourseAi
  module Completions
    module Dialects
      class Claude < Dialect
        class << self
          def can_translate?(model_name)
            model_name.start_with?("claude") || model_name.start_with?("anthropic")
          end
        end

        class ClaudePrompt
          attr_reader :system_prompt
          attr_reader :messages
          attr_reader :tools

          def initialize(system_prompt, messages, tools)
            @system_prompt = system_prompt
            @messages = messages
            @tools = tools
          end

          def has_tools?
            tools.present?
          end
        end

        def tokenizer
          llm_model&.tokenizer_class || DiscourseAi::Tokenizer::AnthropicTokenizer
        end

        def translate
          messages = super

          system_prompt = messages.shift[:content] if messages.first[:role] == "system"

          if !system_prompt && !native_tool_support?
            system_prompt = tools_dialect.instructions.presence
          end

          interleving_messages = []
          previous_message = nil

          messages.each do |message|
            if previous_message
              if previous_message[:role] == "user" && message[:role] == "user"
                interleving_messages << { role: "assistant", content: "OK" }
              elsif previous_message[:role] == "assistant" && message[:role] == "assistant"
                interleving_messages << { role: "user", content: "OK" }
              end
            end
            interleving_messages << message
            previous_message = message
          end

          tools = nil
          tools = tools_dialect.translated_tools if native_tool_support?

          ClaudePrompt.new(system_prompt.presence, interleving_messages, tools)
        end

        def max_prompt_tokens
          return llm_model.max_prompt_tokens if llm_model&.max_prompt_tokens

          # Longer term it will have over 1 million
          200_000 # Claude-3 has a 200k context window for now
        end

        def native_tool_support?
          SiteSetting.ai_anthropic_native_tool_call_models_map.include?(model_name)
        end

        private

        def tools_dialect
          if native_tool_support?
            @tools_dialect ||= DiscourseAi::Completions::Dialects::ClaudeTools.new(prompt.tools)
          else
            super
          end
        end

        def tool_call_msg(msg)
          translated = tools_dialect.from_raw_tool_call(msg)
          { role: "assistant", content: translated }
        end

        def tool_msg(msg)
          translated = tools_dialect.from_raw_tool(msg)
          { role: "user", content: translated }
        end

        def model_msg(msg)
          { role: "assistant", content: msg[:content] }
        end

        def system_msg(msg)
          msg = { role: "system", content: msg[:content] }

          if tools_dialect.instructions.present?
            msg[:content] = msg[:content].dup << "\n\n#{tools_dialect.instructions}"
          end

          msg
        end

        def user_msg(msg)
          content = +""
          content << "#{msg[:id]}: " if msg[:id]
          content << msg[:content]
          content = inline_images(content, msg) if vision_support?

          { role: "user", content: content }
        end

        def inline_images(content, message)
          encoded_uploads = prompt.encoded_uploads(message)
          return content if encoded_uploads.blank?

          content_w_imgs =
            encoded_uploads.reduce([]) do |memo, details|
              memo << {
                source: {
                  type: "base64",
                  data: details[:base64],
                  media_type: details[:mime_type],
                },
                type: "image",
              }
            end

          content_w_imgs << { type: "text", text: content }
        end
      end
    end
  end
end